A new report published by the World Health Organization has revealed "record-breaking progress" in the fight against tropical diseases. Broader poverty issues, however, threaten to stagnate further improvements.

In the past ten years, "unprecedented progress" has been made in tackling tropical diseases worldwide, the World Health Organization (WHO) said Wednesday. To continue targeting invisible killers like Schistosomiasis, however, drug companies, aid organizations and politicians must confront the added challenges created by poverty.

Neglected tropical diseases, also known as NTDs, disfigure and disable millions of people in tropical areas every year. One in six people, mainly from poor communities in Africa, Asia and Latin America, suffer from at least one of the 18 listed NTDs annually.

The debilitating effects of these diseases often keep children out of school and adults out of work, perpetuating cycles of poverty.

"There is no group of diseases that is so intimately linked to poverty," said Dr. Dirk Engels, director of WHO's department of control of neglected tropic diseases.

But the "remarkable achievements" made in modern public healthcare over the past decade have seen millions of people "rescued from disability and poverty," said WHO Director-General, Dr. Margaret Chan.

The global health agency has recorded a dramatic decrease in the number of new cases of some of the worst ailments, including dracunculiasis and trypanosomiasis. The number of people needing treatments has dropped from 2 billion in 2010 to 1.6 billion in 2015.

Only 25 human cases of dracunculiasis, a crippling condition caused by the flesh-burrowing guinea worm, were recorded last year, "putting eradication within reach", WHO said. That's down from nearly 900,000 cases in 1989, when it was endemic in 21 countries.

Without confronting wider poverty-related issues, however, progress could plateau.

An estimated 2.4 billion people still lack basic sanitation facilities like toilets, while nearly two billion people consume water contaminated with fecal matter, significantly increasing their chances of becoming infected by an NTD.

In tropical and sub-tropical areas worldwide, for example, fresh water is sometimes infested with the larvae of parasites known as schistosomes. Once the parasites penetrate human skin, people can become infected by schistosomiasis, also known as bilharzias or "snail fever". But the symptoms of schistosomiasis can take months to surface, slowly causing life-threatening organ damage, including kidney failure, liver fibrosis and bladder cancer.

"They are chronic infections, so you can actually carry these infections for a very long time before you feel really, really sick," says Maurice Odiere from the Kenyan Medical Research Institute KEMRI. "But even when people feel sick it's not like malaria that really puts you down, so people feel lethargy, they'll feel some abdominal pain."

Because the danger is invisible to the human eye and symptoms take longer to appear, people continue taking risks, bathing and working in dirty water to provide for their families.

Simon Ogalla, from the Western Kenyan city of Kisumu, earns his living by cleaning vehicles on the infested shore of Lake Victoria, because the business is good. He can make up to 3,000 kshs a day (30 Euros, $32), but he is aware of the risks, he said.

"You cannot take more than three months before you start feeling that you are weak," Ogalla said. "Something like maybe you are always dizzy or you feel like you want to sleep all the time."

While there is a drug called Praziquantel that effectively treats the disease, it is not safe for children under six, and will not prevent recurring infection. This is why providing education and diversified economic opportunities are as important as medicinal prevention, Odiere said.

"If you treat fishermen or car washers or sand harvesters, you're not giving them an alternative job to do. That's their occupation, that's where they earn their living," he said. "They'll still go back to the waters tomorrow so you might think like you're not doing anything because you're treating them, they're going to be exposed again and then infected."

But providing health education and improving hygiene will only work in combination with expanding access to life-saving drugs. Drug companies must increase donations of existing treatments to make them more accessible, WHO said in its report released on Wednesday.

"The medicines exist but they are too expensive and (neither) people nor countries have the ability to pay," said WHO's Engels.

"A number of companies have accompanied us in the scaling up by making more medicines available. Is that enough? No, there are still diseases that are neglected and we still have problems with access to basic medicines," he added.

Major drug companies that have already jumped on board include GlaxoSmithKline, Sanofi and Merck, which is currently developing a children's formula of Praziquantel to treat schistosomiasis.

The Bill and Melinda Gates Foundation is also backing research and development into NTDs.

"Some of these diseases are on track to be done (eliminated) by 2020, some by 2025," Bill Gates said on Wednesday. "Some will take longer than that."

AllAfrica publishes around 800 reports a day from more than 140 news organizations and over 500 other institutions and individuals, representing a diversity of positions on every topic. We publish news and views ranging from vigorous opponents of governments to government publications and spokespersons. Publishers named above each report are responsible for their own content, which AllAfrica does not have the legal right to edit or correct.

AllAfrica is a voice of, by and about Africa - aggregating, producing and distributing 800 news and information items daily from over 140 African news organizations and our own reporters to an African and global public. We operate from Cape Town, Dakar, Abuja, Monrovia, Nairobi and Washington DC.